Energy efficient power management technologies are fundamentally based upon semiconductor switches. These switches manage power from the watt (W) level to the megawatt (MW) scale. Silicon has been the workhorse for such switches enabled by the insulated gate bipolar transistor (IGBT). Digital power management technologies continue to advance, offering dramatic improvements to power conversion efficiency. Power conversion efficiency of alternating-current to direct-current (AC-DC) and direct-current to direct-current (DC-DC) converters now approach 80-90%. An added benefit of high efficiency power converters is the reduction of losses and reduction in size of inverters and regulators required for controlling power systems. Silicon unfortunately is fundamentally limited in the material properties available for further improvements in reducing losses, reducing cost and increasing performance of the switches required for next generation power converters. A key limitation of silicon is the intrinsic electrical breakdown strength available by the material chemical purity and crystalline structure, which now severely limits how small a switching device can be made and the conversion efficiency that is possible. The critical parameters for an electrical switch are the ON-resistance, the switching or gate capacitance, the breakdown voltage capability of the device, and the thermal conductivity of the semiconductor.
As silicon is fundamentally limited for fulfilling all the criteria listed above, there is a pressing need to explore new materials and devices that can improve the switching speed, increase the breakdown voltage tolerance, reduce the conduction losses when in an ON-state and provide for material properties which enable improved thermal management of the device.